CO ADSORBENTS BASED ON THE FORMATION OF A SUPPORTED CU(CO)CL COMPLEX

CO adsorbents were prepared by forming small CuCl crystallites (simila r to 160 Angstrom) on the surface of an intermediate density silica ge l. CO adsorption by the adsorbents is carried out by converting the Cu Cl crystallites into a bulk [Cu(CO)Cl] complex under moderate CO press ure (e.g., 2.7 atm at 30 degrees C). The bulk [Cu(CO)Cl] decomposes wh en the gas phase CO pressure is below the equilibrium CO pressure (e.g ., 0.5 atm at 30 degrees C). This unique CO adsorption mechanism resul ts in a CO isotherm consisting of separate adsorption and desorption b ranches, i.e., a large hysteresis feature. The threshold pressure of [ Cu(CO)Cl] formation appears to be a function of the size of the CuCl c rystallites.